Solenoid valves may be used as oil control valves to provide oil pressure to latching mechanisms used by components of engine assemblies that use variable valve lift technology. Solenoid valves may thus control the flow of motor oil to the cylinder system, which may in turn, control how the cylinder is coupled to the valve train of the engine assembly. Solenoid valves used as oil control valves may open into supply pressure. Motor oil, under a certain pressure, may flow into a supply port of the oil control valve. In a de-energized state, the oil pressure may push on a poppet which may cause an armature to move so as to prevent oil flow into the oil control valve. In an energized state, a predetermined voltage may be applied to a coil, thereby causing a magnetic force to be generated. The magnetic force may cause the armature to move so as to seal off oil flow to the exhaust port and allow oil flow into the control port of the oil control valve. The flow path from the control port of the oil control valve may lead to the lash adjuster which may facilitate latching and unlatching of the engine valve for a specific cylinder. During the de-energized state of the oil control valve, a minimum pressure to the latching mechanism may be maintained. The oil control valve may prevent a high pressure condition in the oil gallery to the latching mechanism by opening to an exhaust port.
A solenoid valve may include a pole piece. The pole piece may be inserted into a manifold in order to seal a hydraulic passage from an oil supply. The pole piece may be pressed to a particular axial position of the manifold (based on preceding measurements) in order to optimize the performance of the solenoid valve. A metal-to-metal seal may be used between the pole piece and the manifold. In some circumstances, it may be advantageous to employ a more robust seal between the pole piece and the manifold. It may also be advantageous to make additional modifications to the assembly to improve manufacturability.